Revert of [profiler] reduce incorrectly unaccounted ticks. (patchset #4...

Revert of [profiler] reduce incorrectly unaccounted ticks. (patchset #4 id:60001 of https://codereview.chromium.org/2799603005/ )

Reason for revert:
https://build.chromium.org/p/client.v8/builders/V8%20Win32%20-%20debug/builds/8247/steps/Check%20%28flakes%29/logs/CollectOptimizedTople..

Original issue's description:
> [profiler] reduce incorrectly unaccounted ticks.
>
> No longer invalidate the tick sample if there is no JS frame or only one
> non-interpreted JS frame on the stack.
>
> R=jarin@chromium.org
>
> Review-Url: https://codereview.chromium.org/2799603005
> Cr-Commit-Position: refs/heads/master@{#44465}
> Committed: https://chromium.googlesource.com/v8/v8/+/57bef9a1e2621555f70b9258593ae4a4235307ef

TBR=jarin@chromium.org,cbruni@chromium.org,yangguo@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2804593005
Cr-Commit-Position: refs/heads/master@{#44469}

src/profiler/tick-sample.cc

@@ -225,7 +225,12 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
   i::SafeStackFrameIterator it(isolate, reinterpret_cast<i::Address>(regs->fp),
                                reinterpret_cast<i::Address>(regs->sp),
                                js_entry_sp);
-  if (it.done()) return true;
+
+  // If at this point iterator does not see any frames,
+  // is usually means something is wrong with the FP,
+  // e.g. it is used as a general purpose register in the function.
+  // Bailout.
+  if (it.done()) return false;
 
   size_t i = 0;
   if (record_c_entry_frame == kIncludeCEntryFrame &&

test/cctest/cctest.status

@@ -117,7 +117,6 @@
 ['arch == arm64', {
 
   'test-cpu-profiler/CollectDeoptEvents': [PASS, FAIL],
-  'test-cpu-profiler/CollectOptimizedToplevelProfile': [PASS, FAIL],
 
   'test-api/Bug618': [PASS],
 

test/cctest/test-cpu-profiler.cc

@@ -621,51 +621,6 @@ TEST(CollectCpuProfile) {
   profile->Delete();
 }
 
-static const char* cpu_profiler_toplevel_source =
-    "for (var i = 0; i < 1E5; i++) {"
-    "  var s = 0;"
-    "  for (var j = 0; j < 1E2; j++) s += i;"
-    "}";
-
-TEST(CollectOptimizedToplevelProfile) {
-  LocalContext env;
-  v8::HandleScope scope(env->GetIsolate());
-
-  v8::CpuProfiler* profiler = v8::CpuProfiler::New(env->GetIsolate());
-  v8::Local<v8::String> profile_name = v8_str("my_profile");
-
-  profiler->SetSamplingInterval(100);
-  profiler->StartProfiling(profile_name, true);
-  v8::internal::CpuProfiler* iprofiler =
-      reinterpret_cast<v8::internal::CpuProfiler*>(profiler);
-  v8::sampler::Sampler* sampler = iprofiler->processor()->sampler();
-  sampler->StartCountingSamples();
-
-  CompileRun(cpu_profiler_toplevel_source);
-
-  v8::CpuProfile* profile = profiler->StopProfiling(profile_name);
-  reinterpret_cast<i::CpuProfile*>(profile)->Print();
-
-  const v8::CpuProfileNode* root = profile->GetTopDownRoot();
-  v8::Local<v8::String> empty = v8::String::Empty(env->GetIsolate());
-  unsigned toplevel_hitcount = 0;
-  unsigned unaccounted_hitcount = 0;
-  for (int i = 0; i < root->GetChildrenCount(); i++) {
-    const v8::CpuProfileNode* child = root->GetChild(i);
-    if (empty->Equals(env.local(), child->GetFunctionName()).FromJust()) {
-      toplevel_hitcount += child->GetHitCount();
-    } else {
-      unaccounted_hitcount += child->GetHitCount();
-    }
-  }
-  // Check that we are getting more ticks from the toplevel function than
-  // unaccounted ticks.
-  DCHECK(toplevel_hitcount > unaccounted_hitcount);
-
-  profile->Delete();
-  profiler->Dispose();
-}
-
 static const char* hot_deopt_no_frame_entry_test_source =
     "%NeverOptimizeFunction(foo);\n"
     "%NeverOptimizeFunction(start);\n"